feat(parity): wire-stats protocol 2.25.0 + out-format %b/%c/%C

Bump PROTOCOL_VERSION to 2.25.0 and append a report_stats bool to the
config frame, add a STATUS_STATS status, and add process-wide wire byte
counters (protocol_bytes_written/read) for the client.

Render the rsync 3.4.1 --out-format %b (wire bytes sent) and %c (wire
bytes read back) tokens from per-file counter deltas, and %C (whole-file
xxh128 checksum, seed 0) via a new streaming checksum_digest_file().

src/client/client_send.c

@@ -1878,6 +1878,8 @@ static int send_chunk_with_removal(Client* client, Chunk* chunk, Config* config,
                          (stream && !config->use_compression)) &&
                         source_is_regular_file(f);
     SourceFile* source = remove_sources ? source_file_create(f) : NULL;
+    unsigned long long bytes_before = protocol_bytes_written();
+    unsigned long long read_before = protocol_bytes_read();
     int rc = send_single_file(client, f, config, config->use_incremental, use_sendfile);
     if (rc == 1) {
       source_file_destroy(source);
@@ -1887,7 +1889,8 @@ static int send_chunk_with_removal(Client* client, Chunk* chunk, Config* config,
       source_file_destroy(source);
       return -1;
     }
-    change_emit_file_sent(config, f);
+    change_emit_file_sent_bytes(config, f, protocol_bytes_written() - bytes_before,
+                                protocol_bytes_read() - read_before);
     if (source && !array_list_add(remove_sources, source)) {
       source_file_destroy(source);
       return -1;